Single layer multi-touch capacitive imaging sensor

ABSTRACT

Embodiments of the invention generally provide an input device having a reduced system complexity and low production cost. As the size of input devices, such as touch pads and other similar devices increase, the need for an input device that is able to maintain or even improve the touch sensing accuracy without greatly increasing the manufacturing cost becomes increasingly important. Embodiments of the invention may provide an input device that includes an array of capacitive sensing pixels that each include a unique pair of sensor electrodes, wherein at least one of the electrodes in a first pixel is also in communication with another sensor electrode in at least one other pixel, which is not in the same row or column with the first pixel.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/067,801, filed Oct. 30, 2013, which is incorporated by reference inits entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a system andmethod for sensing a position of an input object over a sensing regionof a proximity sensing device.

2. Description of the Related Art

Input devices including proximity sensor devices, also commonly calledtouchpads or touch sensor devices, are widely used in a variety ofelectronic systems. A proximity sensor device typically includes asensing region in which the proximity sensor device determines thepresence, location and/or motion of one or more input objects, such as afinger. Proximity sensor devices may be used to provide interfaces foran electronic system. For example, proximity sensor devices are oftenused as input devices for larger computing systems, such as opaquetouchpads integrated in, or peripheral to notebook or desktop computers.Proximity sensor devices are also often used in smaller computingsystems, such as touch screens integrated in cellular phones. Proximitysensor devices are typically used in combination with other supportingcomponents, such as display or input devices found in the electronic orcomputing system.

In some configurations, the proximity sensor devices are coupled tothese supporting components to provide a desired combined function or toprovide a desirable complete device package. Many commercially availableproximity sensor devices utilize one or more electrical techniques todetermine the presence, location and/or motion of an input object, suchas a capacitive or a resistive sensing technique. Typically, acapacitive sensing type of proximity sensor device utilizes an array ofsensor electrodes and traces to detect the presence, location and/ormotion of an input object. A trace is an electronic component thatconnects an electrode region within a sensor electrode to thecontrolling electronics found in the proximity sensor device. Due to theoften large number of sensor electrodes used to sense the presence andposition of an input object with desirable accuracy, and also the needto connect each of these sensor electrodes to the various signalgeneration and data collection components in the electronic or computingsystem, the cost associated with forming these interconnections, thereliability of the system and the overall size of the proximity sensordevice are often undesirably large and complex. It is a common goal inthe consumer and industrial electronics industries to reduce the costand/or size of the electrical components in the formed electronicdevice. One will note that the cost and size limitations placed on theproximity sensor device are often created by the number of traces thatare required, the number of required connection points, the connectioncomponent's complexity (e.g., number of pins on a connector) and thecomplexity of the flexible components used to interconnect the sensorelectrodes to the control system.

During the operation of a capacitive sensing device the presence of aninput object over the sensing region of the proximity sensor device,which contains the sensor electrodes and their respective traces, theinput object will interfere with the signal provided by the drivenelectrodes (i.e., transmitter electrodes) and also their respectivetraces (i.e., transmitter traces). Unfortunately, the coupling betweenthe transmitter electrodes and the receiver electrodes is also affectedby the interaction of the signal transmitted from the transmitter tracesto the receiver electrodes. Thus, the interaction of an input object andthe signal transmitted from the traces will cause an unwanted parasiticresponse. For example, a finger that is coupled to a particular sensorelectrode is also likely to be coupled to traces that are connected toother sensor electrodes that are not positioned such that they willsignificantly interact with the input object. The controllingelectronics in the proximity sensor device incorrectly interprets thecoupling between the input object and the traces as a response at theother sensor electrodes that are not positioned to directly couple withthe input object. This incorrect interpretation of a response created bythe input object and the local traces is known as a parasitic response.The parasitic response causes the controlling electronics to incorrectlydetermine that one or more phantom input objects are interacting withthe proximity sensor device, and affect the controlling electronicsability to determine the actual location of the actual input object.Moreover, the greater the length of the traces used to interconnect thesensor electrodes to the computer system, the more susceptible theproximity sensor device is to interference, such as electromagneticinterference (EMI), and the more susceptible the proximity sensor deviceis to a parasitic response. The parasitic response and interferenceprovided by these supporting components will adversely affect thereliability and accuracy of the data collected by the proximity sensingdevice.

Therefore, there is a need for an apparatus and method of forming aproximity sensing device that is reliable, provides consistent andaccurate position sensing results, is inexpensive to produce and can beintegrated within a desirably sized electronic system.

SUMMARY OF THE INVENTION

Embodiment of the invention provide an input device that includes anarray of capacitive sensing pixels that each include a unique pair ofsensor electrodes, wherein at least one of the electrodes in a firstcapacitive sensing pixel is also in communication with another sensorelectrode in at least one other capacitive sensing pixel. The at leastone other capacitive sensing pixel also need not be in the same row orcolumn with the first capacitive sensing pixel. Advantageously,techniques of the present invention enable an input device to determinemore accurately and more reliably a location of an input object coveringa capacitive sensing region of the input device.

Embodiment of the invention may further provide a capacitive imagesensor, comprising a first array of first sensor electrodes disposed ona surface of a substrate, wherein each of the first sensor electrodescomprise a first electrode region, and each of the first electroderegions are aligned in a first direction that is parallel to thesurface, a first array of second sensor electrodes disposed on thesurface of the substrate, wherein each of the second sensor electrodescomprise a second electrode region, and each of the first electroderegions in the first array of first sensor electrodes are positioned todirectly capacitively couple to at least a portion of a second sensorelectrode in the first array of second sensor electrodes. The capacitiveimage sensor may further include a second array of first sensorelectrodes disposed on the surface of the substrate, wherein each of thefirst electrode regions of the first sensor electrodes in the secondarray are aligned in the first direction, and a second array of secondsensor electrodes disposed on the surface of the substrate, wherein eachof the first electrode regions in the second array of first sensorelectrodes are positioned to directly capacitively couple to at least aportion of a second sensor electrode in the second array of secondsensor electrodes. The second array of first sensor electrodes in thecapacitive image sensor can be positioned a distance in a seconddirection from the first array of first sensor electrodes, where thesecond direction is not parallel to the first direction. The first arrayof first sensor electrodes and the second array of first sensorelectrodes in the capacitive image sensor can be disposed on the surfaceof the substrate between the first array of second sensor electrodes andthe second array of second sensor electrodes, and at least one secondsensor electrode in the first array of second sensor electrodes iselectrically coupled to at least one second sensor electrode in thesecond array of second sensor electrodes.

Embodiment of the invention may further provide a capacitive imagesensor that comprises a first, second and third set of sensor electrodearrays. The first set of set of sensor electrode arrays may comprise afirst array of first sensor electrodes disposed on a surface of asubstrate, wherein each of the first sensor electrodes comprise a firstelectrode region, and each of the first electrode regions are aligned ina first direction that is parallel to the surface, a first array ofsecond sensor electrodes disposed on the surface of the substrate,wherein each of the second sensor electrodes comprise a second electroderegion, and each of the first electrode regions in the first array offirst sensor electrodes are positioned to directly capacitively coupleto at least a portion of a second sensor electrode in the first array ofsecond sensor electrodes. The second set of set of sensor electrodearrays may comprise a second set of sensor electrode arrays comprising asecond array of first sensor electrodes disposed on the surface of thesubstrate, wherein each of the first electrode regions of the firstsensor electrodes in the second array are aligned in the firstdirection, and a second array of second sensor electrodes disposed onthe surface of the substrate, wherein each of the first electroderegions in the second array of first sensor electrodes are positioned todirectly capacitively couple to at least a portion of a second sensorelectrode in the second array of second sensor electrodes. The third setof set of sensor electrode arrays may comprise a third set of sensorelectrode arrays comprising a third array of first sensor electrodesdisposed on the surface of the substrate, wherein each of the firstelectrode regions of the first sensor electrodes in the third array arealigned in the first direction, and a third array of second sensorelectrodes disposed on the surface of the substrate, wherein each of thefirst electrode regions in the third array of first sensor electrodesare positioned to directly capacitively couple to at least a portion ofa second sensor electrode in the third array of second sensorelectrodes. The second and third arrays of first sensor electrodes inthe capacitive image sensor can each be positioned a distance in asecond direction from the first array of first sensor electrodes, andthe second direction is not parallel to the first direction. Thecapacitive image sensor may also be configured so that the third set ofsensor electrode arrays is disposed between the first set of sensorelectrode arrays and the second set of sensor electrode arrays, andwherein at least one second sensor electrode in the first array ofsecond sensor electrodes is electrically coupled to at least one secondsensor electrode in the second array of second sensor electrodes.

Embodiment of the invention may further provide a touch screen,comprising a display, a plurality of sensor electrodes disposed on asubstrate of the display, the plurality of sensor electrodes comprisinga first array of first sensor electrodes disposed on a surface of asubstrate, wherein each of the first sensor electrodes comprise a firstelectrode region and a trace that is coupled to the first electroderegion, and each of the first electrode regions are aligned along afirst direction that is parallel to the surface. The touch screen mayalso include a first array of second sensor electrodes disposed on thesurface of the substrate, wherein each of the second sensor electrodescomprise a second electrode region and a trace that is coupled to thesecond electrode region, and each of the first electrode regions in thefirst array of first sensor electrodes are positioned to directlycapacitively couple to at least a portion of a second sensor electrodein the first array of second sensor electrodes. The touch screen mayalso include a second array of first sensor electrodes disposed on thesurface of the substrate, wherein each of the first electrode regions ofthe first sensor electrodes in the second array are aligned along thefirst direction, and a second array of second sensor electrodes disposedon the surface of the substrate. Each of the first electrode regions inthe second array of first sensor electrodes are positioned to directlycapacitively couple to at least a portion of a second sensor electrodein the second array of second sensor electrodes, and the second array offirst sensor electrodes are positioned a distance in a second directionfrom the first array of first sensor electrodes, and the seconddirection is not parallel to the first direction, The first array offirst sensor electrodes and the second array of first sensor electrodesare disposed on the surface of the substrate between the first array ofsecond sensor electrodes and the second array of second sensorelectrodes, and at least one second sensor electrode in the first arrayof second sensor electrodes is electrically coupled to at least onesecond sensor electrode in the second array of second sensor electrodes,and a sensor processor communicatively coupled to the traces of thefirst and second sensor electrodes, and configured to receive resultingsignals received by one or more of the second sensor electrodes when afirst sensor electrode is driven for capacitive sensing.

Embodiment of the invention may further provide a touch screen,comprising a display, a plurality of sensor electrodes disposed on asubstrate of the display, the plurality of sensor electrodes comprisinga first, second and third set of sensor electrode arrays. The first setof sensor electrodes may comprise a first array of first sensorelectrodes disposed on a surface of a substrate, wherein each of thefirst sensor electrodes comprise a first electrode region and a tracethat is coupled to the first electrode region, and each of the firstelectrode regions are aligned in a first direction that is parallel tothe surface, and a first array of second sensor electrodes disposed onthe surface of the substrate, wherein each of the second sensorelectrodes in the first array comprise a second electrode region and atrace that is coupled to the second electrode region, and each of thefirst electrode regions in the first array of first sensor electrodesare positioned to directly capacitively couple to at least a portion ofa second sensor electrode in the first array of second sensorelectrodes. The second set of sensor electrodes may comprise a secondset of sensor electrode arrays comprising a second array of first sensorelectrodes disposed on the surface of the substrate, wherein each of thefirst electrode regions of the first sensor electrodes in the secondarray are aligned in the first direction; and a second array of secondsensor electrodes disposed on the surface of the substrate, wherein eachof the first electrode regions in the second array of first sensorelectrodes are positioned to directly capacitively couple to at least aportion of a second sensor electrode in the second array of secondsensor electrodes. The third set of sensor electrodes may comprise athird set of sensor electrode arrays comprising a third array of firstsensor electrodes disposed on the surface of the substrate, wherein eachof the first electrode regions of the first sensor electrodes in thethird array are aligned in the first direction; and a third array ofsecond sensor electrodes disposed on the surface of the substrate,wherein each of the first electrode regions in the third array of firstsensor electrodes are positioned to directly capacitively couple to atleast a portion of a second sensor electrode in the third array ofsecond sensor electrodes. The second and third arrays of first sensorelectrodes in the touch screen may each be positioned a distance in asecond direction from the first array of first sensor electrodes, wherethe second direction is not parallel to the first direction. The thirdset of sensor electrode arrays in the touch screen can be disposedbetween the first set of sensor electrode arrays and the second set ofsensor electrode arrays. The touch screen may also further comprise atleast one second sensor electrode in the first array of second sensorelectrodes is electrically coupled to at least one second sensorelectrode in the second array of second sensor electrodes, and a sensorprocessor communicatively coupled to the traces of the first and secondsensor electrodes, and configured to receive resulting signals receivedby one or more of the second sensor electrodes when a first sensorelectrode is driven for capacitive sensing.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a schematic block diagram of an exemplary input device, inaccordance with embodiments of the invention.

FIG. 2A is a schematic diagram illustrating an input device, accordingto one or more of the embodiments described herein.

FIG. 2B is a schematic diagram illustrating a portion of an inputdevice, according to one or more of the embodiments described herein.

FIG. 2C is a schematic view of sensing elements disposed in an array ofsensing elements (not shown) of the input device, according to one ormore of the embodiments described herein.

FIG. 3 schematically illustrates a sensor electrode configurationaccording to one or more of the embodiments described herein.

FIG. 4 is a schematic diagram illustrating two sets of sensor electrodearrays, which are disposed within a portion of a sensing region and eachinclude arrays of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 5 is a schematic diagram illustrating four sets of sensor electrodearrays, which are disposed within a portion of a sensing region and eachinclude arrays of sensor electrodes, according to one or more of theembodiments described herein.

FIG. 6A is a schematic diagram illustrating four sets of sensorelectrode arrays, which are disposed within a portion of a sensingregion and each include arrays of sensor electrodes, according to one ormore of the embodiments described herein.

FIG. 6B is a schematic diagram illustrating four sets of sensorelectrode arrays, which are disposed within a portion of a sensingregion and each include arrays of sensor electrodes, according to one ormore of the embodiments described herein.

FIG. 7 is a schematic diagram illustrating sets of sensor electrodearrays that are interconnected, and are disposed within sectors of thesensing region of an input device, according to one or more of theembodiments described herein.

FIG. 8 is a schematic diagram illustrating sets of sensor electrodearrays that are interconnected, and are disposed within sectors of thesensing region of an input device, according to one or more of theembodiments described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation. The drawings referred to here should not beunderstood as being drawn to scale unless specifically noted. Also, thedrawings are often simplified and details or components omitted forclarity of presentation and explanation. The drawings and discussionserve to explain principles discussed below, where like designationsdenote like elements.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. Furthermore, there is no intention to be bound by anyexpressed or implied theory presented in the preceding technical field,background, brief summary or the following detailed description.

General Overview

Embodiments of the invention generally provide an input device having areduced system complexity and low production cost. As the size of inputdevices, such as touch pads and other similar devices increase, the needfor an input device that is able to maintain or even improve the touchsensing accuracy without greatly increasing the manufacturing costbecomes increasingly important. Embodiments of the invention may providean input device that has an electrode configuration which has a similarsensing electrode size, electrode pitch and electrode density (e.g.,electrodes per unit area) distributed over a larger sensing region of alarger input device without greatly increasing the cost and complexityassociated with the increased number of sensor electrodes and supportingsignal processing components needed to compensate for the increased sizeof the input device. Accordingly, the embodiments of the invention canbe used to reduce the cost of existing input device designs and minimizethe costs required to produce the next generation devices.

Embodiments of the invention may provide an input device that includesan array of capacitive sensing pixels that each include a unique pair ofsensor electrodes, wherein at least one of the electrodes in a firstcapacitive sensing pixel is also in communication with another sensorelectrode in at least one other capacitive sensing pixel, which is notin the same row or column with the first pixel. Advantageously,techniques of the present invention also enable an input device todetermine more accurately and more reliably a location of an inputobject covering a capacitive sensing region of the input device. One ormore of the embodiments discussed herein may also include an inputdevice that has a plurality of sensing elements that are interconnectedin desired way to reliably and accurately acquire positional informationof an input object. The acquired positional information may be used tocontrol the system's operation mode, as well as graphical user interface(GUI) actions, such as cursor movement, selection, menu navigation, andother functions. In one embodiment, one or more capacitive sensingtechniques and/or novel sensor electrode array configurations are usedto reduce or minimize the number of traces and/or sensor electrodesrequired to sense the positional information of an input object withinthe sensing region of the input device.

System Overview

FIG. 1 is a block diagram of an exemplary input device 100, inaccordance with embodiments of the invention. In FIG. 1, the inputdevice 100 is a proximity sensor device (e.g., “touchpad,” “touchscreen,” “touch sensor device”) configured to sense inputs provided byone or more input objects 140 positioned in a sensing region 120.Example input objects include fingers and styli, as shown in FIG. 1. Insome embodiments of the invention, the input device 100 may beconfigured to provide input to an electronic system 150, which issometimes referred to herein as the “host.” As used in this document,the term “electronic system” (or “electronic device”) broadly refers toany system capable of electronically processing information. Somenon-limiting examples of electronic systems include personal computersof all sizes and shapes, such as desktop computers, laptop computers,netbook computers, tablets, web browsers, e-book readers, and personaldigital assistants (PDAs). Additional examples of electronic systemsinclude composite input devices, such as physical keyboards that includeinput device 100 and separate joysticks or key switches. Furtherexamples of electronic systems 150 include peripherals, such as datainput devices (e.g., remote controls and mice) and data output devices(e.g., display screens and printers). Other examples include remoteterminals, kiosks, video game machines (e.g., video game consoles,portable gaming devices, and the like), communication devices (e.g.,cellular phones, such as smart phones), and media devices (e.g.,recorders, editors, and players such as televisions, set-top boxes,music players, digital photo frames, and digital cameras). Additionally,the electronic system could be a host or a slave to the input device.

The input device 100 can be implemented as a physical part of theelectronic system 150, or can be physically separate from the electronicsystem. As appropriate, the input device 100 may communicate with partsof the electronic system 150 using any one or more of the following:buses, networks, and other wired or wireless interconnections. Examplesinclude I²C, SPI, PS/2, Universal Serial Bus (USB), Bluetooth, RF, andIRDA.

Sensing region 120 encompasses any space above, around, in and/or nearthe input device 100 in which the input device 100 is able to detectuser input by one or more input objects 140. The sizes, shapes, andlocations of particular sensing regions may vary widely from embodimentto embodiment. In some embodiments, the sensing region 120 extends froma surface of the input device 100 in one or more directions into spaceuntil signal-to-noise ratios prevent sufficiently accurate objectdetection. The distance to which this sensing region 120 extends in aparticular direction, in various embodiments, may be on the order ofless than a millimeter, millimeters, centimeters, or more, and may varysignificantly with the type of sensing technology used and the accuracydesired. Thus, some embodiments sense input that comprises no contactwith any surfaces of the input device 100, contact with an input surface(e.g., a touch surface) of the input device 100, contact with an inputsurface of the input device 100 coupled with some amount of appliedforce or pressure, and/or a combination thereof. In various embodiments,input surfaces may be provided by surfaces of casings within which thesensor electrodes reside, by face sheets applied over the sensorelectrodes or any casings, etc. In some embodiments, the sensing region120 has a rectangular shape when projected onto an input surface of theinput device 100.

The input device 100 may utilize any combination of sensor componentsand sensing technologies to detect user input in the sensing region 120.The input device 100 generally comprises one or more sensing elements121 for detecting user input. As several non-limiting examples, the oneor more sensing elements 121 in the input device 100 may use capacitive,elastive, resistive, inductive, magnetic acoustic, ultrasonic, and/oroptical techniques to detect the position or motion of the inputobject(s) 140. Some implementations are configured to provide sensingimages that span one, two, three, or higher dimensional spaces.

In FIG. 1, a processing system 110 is shown as part of the input device100. The processing system 110 is configured to operate the hardware ofthe input device 100 to detect input in the sensing region 120. Theprocessing system 110 comprises parts of or all of one or moreintegrated circuits (ICs) and/or other circuitry components. In someembodiments, the processing system 110 also compriseselectronically-readable instructions, such as firmware code, softwarecode, and/or the like. In some embodiments, components composing theprocessing system 110 are located together, such as near sensingelement(s) 121 of the input device 100. In other embodiments, componentsof processing system 110 are physically separate with one or morecomponents close to sensing elements 121 of input device 100, and one ormore components elsewhere. For example, the input device 100 may be aperipheral coupled to a desktop computer, and the processing system 110may comprise software configured to run on a central processing unit ofthe desktop computer and one or more ICs (perhaps with associatedfirmware) separate from the central processing unit. As another example,the input device 100 may be physically integrated in a phone, and theprocessing system 110 may comprise circuits and firmware that are partof a main processor of the phone. In some embodiments, the processingsystem 110 is dedicated to implementing the input device 100. In otherembodiments, the processing system 110 also performs other functions,such as operating display screens, driving haptic actuators, etc.

The processing system 110 may be implemented as a set of modules thathandle different functions of the input device 100. Each module maycomprise circuitry that is a part of the processing system 110,firmware, software, or a combination thereof. In various embodiments,different combinations of modules may be used. In one example, modulesinclude hardware operation modules for operating hardware such assensing elements and display screens, data processing modules forprocessing data, such as sensor signals, and positional information, andreporting modules for reporting information. In another example, modulesinclude sensor operation modules configured to operate sensingelement(s) to detect input, identification modules configured toidentify gestures such as mode changing gestures, and mode changingmodules for changing operation modes.

In some embodiments, the processing system 110 responds to user input(or lack of user input) in the sensing region 120 directly by causingone or more actions. In one example, as noted above, actions may includechanging operation modes, as well as GUI actions, such as cursormovement, selection, menu navigation, and other functions. In someembodiments, the processing system 110 provides information about theinput (or lack of input) to some part of the electronic system (e.g., toa central processing system of the electronic system that is separatefrom the processing system 110, if such a separate central processingsystem exists). In some embodiments, some part of the electronic systemprocess information received from the processing system 110 is used toact on user input, such as to facilitate a full range of actions,including mode changing actions and GUI actions. For example, in someembodiments, the processing system 110 operates the sensing element(s)121 of the input device 100 to produce electrical signals indicative ofinput (or lack of input) in the sensing region 120. The processingsystem 110 may perform any appropriate amount of processing on theelectrical signals in producing the information provided to theelectronic system. For example, the processing system 110 may digitizeanalog electrical signals obtained from the sensing elements 121. Asanother example, the processing system 110 may perform filtering orother signal conditioning. As yet another example, the processing system110 may subtract or otherwise account for a baseline set of data (e.g.,baseline image), such that the information reflects a difference betweenthe acquired electrical signals (e.g., sensing image) and the baseline.As yet further examples, the processing system 110 may determinepositional information, recognize inputs as commands, recognizehandwriting, and the like.

“Positional information” as used herein broadly encompasses absoluteposition, relative position, velocity, acceleration, and other types ofspatial information. Exemplary “zero-dimensional” positional informationincludes near/far or contact/no contact information. Exemplary“one-dimensional” positional information includes positions along anaxis. Exemplary “two-dimensional” positional information includesmotions in a plane. Exemplary “three-dimensional” positional informationincludes instantaneous or average velocities in space. Further examplesinclude other representations of spatial information. Historical dataregarding one or more types of positional information may also bedetermined and/or stored, including, for example, historical data thattracks position, motion, or instantaneous velocity over time.

In some embodiments, the input device 100 is implemented with additionalinput components that are operated by the processing system 110 or bysome other processing system. These additional input components mayprovide redundant functionality for input in the sensing region 120, orsome other functionality. FIG. 1 shows buttons 130 near the sensingregion 120 that can be used to facilitate selection of items using theinput device 100. Other types of additional input components includesliders, balls, wheels, switches, and the like. Conversely, in someembodiments, the input device 100 may be implemented with no other inputcomponents.

In some embodiments, the input device 100 comprises a touch screeninterface, and the sensing region 120 overlaps at least part of anactive area of a display screen of a display device (not shown). Forexample, the input device 100 may comprise substantially transparentsensor electrodes overlaying the display screen and provide a touchscreen interface for the associated electronic system. The displayscreen may be any type of dynamic display capable of displaying a visualinterface to a user, and may include any type of light emitting diode(LED), organic LED (OLED), cathode ray tube (CRT), liquid crystaldisplay (LCD), plasma, electroluminescence (EL), or other displaytechnology. The input device 100 and the display device may sharephysical elements. Some embodiments of the input device 100 include atleast part of the display device. For example, some embodiments mayutilize some of the same electrical components for displaying andsensing. In some examples, the display screen of the display device maybe operated in part or in total by the processing system 110.

It should be understood that while many embodiments of the presenttechnology are described in the context of a fully functioningapparatus, the mechanisms of the present technology are capable of beingdistributed as a program product (e.g., software) in a variety of forms.For example, the mechanisms of the present technology may be implementedand distributed as a software program on information bearing media thatare readable by electronic processors (e.g., non-transitorycomputer-readable and/or recordable/writable information bearing mediareadable by the processing system 110). Additionally, the embodiments ofthe present technology apply equally regardless of the particular typeof medium used to carry out the distribution. Examples ofnon-transitory, electronically readable media include various discs,memory sticks, memory cards, memory modules, and the like.Electronically readable media may be based on flash, optical, magnetic,holographic, or any other storage technology.

In many embodiments, the positional information of the input object 140relative to the sensing region 120 is monitored or sensed by use of oneor more sensing elements 121 (FIG. 1) that are positioned to detect its“positional information.” In general, the sensing elements 121 maycomprise one or more sensing elements or components that are used todetect the presence of an input object. As discussed above, the one ormore sensing elements 121 of the input device 100 may use capacitive,elastive, resistive, inductive, magnetic acoustic, ultrasonic, and/oroptical techniques to sense the positional information of an inputobject. While the information presented below primarily discuses theoperation of an input device 100, which uses capacitive sensingtechniques to monitor or determine the positional information of aninput object 140 this configuration is not intended to be limiting as tothe scope of the invention described herein, since other sensingtechniques may be used.

In some resistive implementations of the input device 100, a flexibleand conductive first layer is separated by one or more spacer elementsfrom a conductive second layer. During operation, one or more voltagegradients are created across the layers. Pressing the flexible firstlayer may deflect it sufficiently to create electrical contact betweenthe layers, resulting in voltage outputs reflective of the point(s) ofcontact between the layers. These voltage outputs may be used todetermine positional information.

In some inductive implementations of the input device 100, one or moresensing elements pick up loop currents induced by a resonating coil orpair of coils. Some combination of the magnitude, phase, and frequencyof the currents may then be used to determine positional information.

In one embodiment of the input device 100, the sensing element 121 is acapacitive sensing element that is used to sense the positionalinformation of the input object(s). In some capacitive implementationsof the input device 100, voltage or current is applied to the sensingelements to create an electric field between an electrode and ground.Nearby input objects 140 cause changes in the electric field, andproduce detectable changes in capacitive coupling that may be detectedas changes in voltage, current, or the like. Some capacitiveimplementations utilize arrays or other regular or irregular patterns ofcapacitive sensing elements to create electric fields. In somecapacitive implementations, portions of separate sensing elements may beohmically shorted together to form larger sensor electrodes. Somecapacitive implementations utilize resistive sheets, which may beuniformly resistive.

Some capacitive implementations utilize “self capacitance” (or “absolutecapacitance”) sensing methods based on changes in the capacitivecoupling between one or more sensing elements, or one or more sensorelectrodes, and an input object. In various embodiments, an at leastpartially grounded input object positioned near the sensor electrodesalters the electric field near the sensor electrodes, thus changing themeasured capacitive coupling of the sensor electrodes to ground. In oneimplementation, an absolute capacitance sensing method operates bymodulating sensor electrodes with respect to a reference voltage (e.g.,system ground), and by detecting the capacitive coupling between thesensor electrodes and the at least partially grounded input object(s).

Some capacitive implementations utilize “mutual capacitance” (or“transcapacitance”) sensing methods based on changes in the capacitivecoupling between two or more sensing elements (e.g., sensor electrodes).In various embodiments, an input object near the sensor electrodesalters the electric field created between the sensor electrodes, thuschanging the measured capacitive coupling. In one implementation, atranscapacitive sensing method operates by detecting the capacitivecoupling between one or more transmitter sensor electrodes (also“transmitter electrodes,” “transmitting electrodes” or “transmitters”)and one or more receiver sensor electrodes (also “receiver electrodes”or “receiving electrodes”). Transmitter sensor electrodes may bemodulated relative to a reference voltage (e.g., system ground) totransmit transmitter signals. Receiver sensor electrodes may be heldsubstantially constant relative to the reference voltage to facilitatereceipt of “resulting signals.” A “resulting signal” may compriseeffect(s) corresponding to one or more transmitter signals, and/or toone or more sources of environmental interference (e.g., otherelectromagnetic signals). Sensor electrodes may be dedicatedtransmitters or receivers, or may be configured to both transmit andreceive. In some implementations user input from an actively modulateddevice (e.g. an active pen) may act as a transmitter such that each ofthe sensor electrodes act as a receiver to determine the position of theactively modulated device.

Most conventional multi-touch sensing sensor devices, in which thelocation of more than one finger or other input can be accuratelydetermined, comprise a matrix of transmitter sensor electrodes andreceiver sensor electrodes. Conventionally, during operation, capacitiveimages are formed by measuring the capacitance formed between eachtransmitter and receiver sensor electrode (referred to as“transcapacitance” or “mutual capacitance”), forming a matrix or grid ofcapacitive detecting elements across the sensing region 120. Thepresence of an input object (such as a finger or other object) at ornear an intersection between transmitter and receiver sensor electrodeschanges the measured “transcapacitance”. These changes are localized tothe location of object, where each transcapacitive measurement is apixel of a “capacitive image” and multiple transcapacitive measurementscan be utilized to form a capacitive image of the object.

Herein sensor design and sensing scheme embodiments are described thatallow the creation of 2-D capacitance images using a single sensinglayer in which all of the transmitting and receiving sensor electrodesare disposed in a single common layer with one another without the useof jumpers within the sensor area. The electronics to drive the sensorare located in a processing system, such as processing system 110described herein. These described embodiments also facilitate contactsensing, proximity sensing, and position sensing. These describedembodiments also facilitate “multi-touch” sensing, such as two fingerrotation gestures and two finger pinch gestures, but with a lessexpensive sensor compared to a sensor that utilizes sensor electrodes inmultiple layers. The reduced number of layers used to form the inputdevice described herein versus other conventional position sensingdevices also equates to fewer production steps, which in itself willreduce the production cost of the device. The reduction in the layers ofthe input device also decreases interference or obscuration of an imageor display that is viewed through the sensor, thus lending itself toimproved optical quality of the formed input device when it isintegrated with a display device. Additional electrodes involved insensing the shape of the electric fields of the transmitters andreceivers, such as floating electrodes or shielding electrodes, may beincluded in the device and may be placed on other substrates or layers.The electrodes may be part of a display (share a substrate) and may evenshare functionality with the display (used for both display and sensingfunctionality). For example electrodes may be patterned in the Colorfilter of an LCD (Liquid Crystal Display) or on the sealing layer of anOLED (Organic Light Emitting Diode) display. Alternately, sensingelectrodes within the display or on TFT (Thin Film Transistor) layer ofan active matrix display may also be used as gate or source drivers.Such electrodes may be patterned (e.g. spaced or oriented at an anglerelative to the pixels) such that they minimize any visual artifacts.Furthermore, they may use hiding layers (e.g. Black Mask between pixels)to hide at least some portion of one or more conductive electrodes.

FIG. 2A is a schematic top view of a portion of an input device 295 thatillustrates a portion of a sensor electrode pattern that may be used tosense the positional information of an input object within the sensingregion 120 using a transcapacitive sensing method. One will note thatthe input device 295 may be formed as part of a larger input device 100,which is discussed above. In general, the sensor electrode patterndisclosed herein comprises a sensor array collection 200 that includes aplurality of sets of sensor electrode arrays 210 that include aplurality of arrays of sensor electrodes that include a plurality ofsensor electrodes, such as sensor electrodes 202 and 211, that arearranged and interconnected in a desirable manner to reduce or minimizethe number of traces and/or sensor electrodes required to sense thepositional information of an input object within the sensing region 120of the input device 295. For clarity of illustration and description,while FIG. 2A illustrates a pattern of simple rectangles used torepresent the sensor electrodes, this configuration is not meant to belimiting and in other embodiments, various other sensor electrode shapesmay be used as discussed further herein. In other some embodiments,sensing elements 121 comprise two or more sensor electrodes, forexample, sensor electrodes 202 and 211 that may be similar or differentin size and/or shape. In general, a sensor electrode includes anelectrode region, or portion of the sensor electrode that is intended tocapacitively couple to another sensor electrode, and a trace. In oneexample the electrode region has a polygonal shape, such as electroderegions 203 or electrode region 204 illustrated in FIG. 2C. A trace,such as trace 212 or trace 213 in FIG. 2A, is used to connect theelectrode region to other electrode regions or other the electroniccomponents in the input device 295. In one example, as shown, thesesensor electrodes are disposed in a sensor electrode pattern thatcomprises a first plurality of sensor electrodes 202 (e.g., 15 shown)and a second plurality of sensor electrodes 211 (e.g., 30 shown), whichare disposed on the same layer as the first plurality of sensorelectrodes 202. Sensor electrodes 202 and sensor electrodes 211 aretypically ohmically isolated from each other, by use of insulatingmaterials or a physical gap formed between the electrodes to preventthem from electrically shorting to each other. In some configurations,two or more sensing elements 121 may form a larger unit cell 122. A unitcell 122 includes a grouping of sensor electrodes that are repeatedwithin a sensor electrode array 210 and/or in a repeating pattern acrossthe sensing region 120 (e.g., multiple sensor electrode arrays 210). Theunit cell 122 is the smallest unit a symmetric grouping of sensorelectrodes can be broken into within an electrode pattern formed acrossthe sensing region 120. As illustrated in FIG. 2A, in one example, theunit cell 122 includes two sensing elements 121, which each contain aportion of the sensor electrode 202 and the sensor electrode 211, andthus the unit cell 122 comprises a sensor electrode 202 and two sensorelectrodes 211. One will note that the sensor electrode pattern of FIG.2A may alternatively utilize various sensing techniques, such as mutualcapacitive sensing, absolute capacitive sensing, elastive, resistive,inductive, magnetic acoustic, ultrasonic, or other useful sensingtechniques, without deviating from the scope of the invention describedherein. Sensor electrode 202 maybe be a transmitter and sensor electrode211 maybe a receiver, or vice versa (the other way around) withtypically similar imaging capability.

In one embodiment, as illustrated in FIG. 2A, the sensing elements 121may comprise a plurality of transmitter and receiver electrodes that areformed in a single layer on a surface of a substrate 209. In oneconfiguration of the input device 295, each of the sensor electrodes maycomprise one or more transmitter electrodes (e.g. sensor electrodes 202)that are disposed proximate to one or more receiver electrodes (e.g.sensor electrodes 211). In one example, a transcapacitive sensing methodusing the single layer sensor electrode design, may operate by detectingthe change in capacitive coupling between one or more of the driventransmitter sensor electrodes and one or more of the receiverelectrodes, as similarly discussed above. In such embodiments, thetransmitter and receiver electrodes may be disposed in such a way suchthat jumpers and/or extra layers used to form the area of capacitivesensing pixels are not required. In various embodiments, the transmitterelectrodes and receiver electrodes may be formed in an array on thesurface of a substrate 209 by first forming a blanket conductive layeron the surface of the substrate 209 and then performing an etchingand/or patterning process (e.g., lithography and wet etch, laserablation, etc.) that ohmically isolates each of the transmitterelectrodes and receiver electrodes from each other. In otherembodiments, the sensor electrodes may be patterned using deposition andscreen printing methods. As illustrated in FIG. 2A, these sensorelectrodes may be disposed in an array that comprises a rectangularpattern of sensing elements 121, which may comprise one or moretransmitter electrodes and one or more receiver electrodes. In oneexample, the blanket conductive layer used to form the transmitterelectrodes and receiver electrodes comprises a thin metal layer (e.g.,copper, aluminum, etc.) or a thin transparent conductive oxide layer(e.g., ATO, ITO, Zinc oxide) that is deposited using conventiondeposition techniques known in the art (e.g., PVD, CVD). In variousembodiments, patterned isolated conductive electrodes (e.g.,electrically floating electrodes) may be used to improve visualappearance. In one or more of the embodiments described herein, thesensor electrodes are formed from a material that is substantiallyoptically clear, and thus, in some configurations, can be disposedbetween a display device and the input device user.

The areas of localized capacitive coupling formed between at least aportion of one or more sensor electrodes 202 and at least a portion ofone or more sensor electrodes 211 may be termed a “capacitive pixel,”“capacitive sensing pixel” or also referred to herein as the sensingelement 121. For example, as shown in FIG. 2A, the capacitive couplingin a sensing element 121 may be created by the electric field formedbetween at least a portion of the sensor electrodes 202 and a sensorelectrode 211, which changes as the proximity and motion of inputobjects across the sensing region changes.

In transcapacitive sensing designs, since a driven transmitter electrodecan capacitively couple with multiple receiver electrodes disposedwithin the sensing region 120, the phrase “directly coupled to” or“directly capacitively coupled to” are used herein to help clarify thecapacitive sensing elements that are intended to form a part of asensing element 121. In general, directly coupled sensor electrodesinclude a transmitter electrode and a receiver electrode, which is thetransmitter electrode's nearest neighbor. One skilled in the art willappreciate that the capacitive coupling between nearest neighbors isbelieved to be created by the electric fields formed at or near theedges of the nearest neighbor electrodes. Typically, the surface area ofa sensor electrode has a much smaller effect on the capacitive couplingbetween the electrodes. The phrase “adjacent sensor electrodes” isgenerally used herein to define nearest neighbor sensor electrodes thatare only separated by a physical gap or have a minimal capacitivecoupling affecting obstruction disposed between the adjacent electrodes.In one example, the transmitter electrode 202 ₁ in FIG. 2A can be saidto be adjacent to receiver electrode 211 ₁, since the sensor electrodesare only separated by a physical gap. In another example, thetransmitter electrode 202 ₂ can be said to be adjacent to receiverelectrode 211 ₂ even though a trace 213 may be disposed between theelectrodes, since the size of the trace is typically smaller than theuseful electrode region of the sensor electrodes. Also, one will notethat the measured change in capacitance created by the interaction of aninput object 140 and the electric field lines created between thetransmitter electrode 202 ₂ and receiver electrode 211 ₂ is primarilydue to the interaction of the input object 140 and the electric fieldlines that pass through a region that is above the plane, or planes,that the electrodes reside in, such as above the surface of a lensdisposed over a portion of the input device 100. Therefore, in thisexample, the presence of the trace 213 between the transmitter electrode202 ₂ and receiver electrode 211 ₂ will have little effect on themeasured change in capacitance signal received by the processing system110 due to the presence of the input object 140 near the transmitterelectrode 202 ₂ and receiver electrode 211 ₂. Elements that would tendto obstruct the capacitive coupling between adjacent sensor electrodesgenerally include ground planes, portions of a grounded electrode regionof another sensor electrode, and other electric field thieving elements.

In some embodiments, the sensing elements 121 are “scanned” to determinethese capacitive couplings. The input device 295 may be operated suchthat one transmitter electrode transmits at one time, or multipletransmitter electrodes transmit at the same time. Where multipletransmitter electrodes transmit simultaneously, these multipletransmitter electrodes may transmit the same transmitter signal andeffectively produce an effectively larger transmitter electrode, orthese multiple transmitter electrodes may transmit different transmittersignals. In one example, the transmitter electrodes are the sensorelectrodes 202 and the receiver electrodes are the sensor electrodes211. For example, in one configuration, multiple sensor electrodes 202transmit different transmitter signals according to one or more codingschemes that enable their combined effects on the resulting signalsreceived by the receiving sensor electrodes, or sensor electrodes 211,to be independently determined. The direct effect of a user input whichis coupled to the device may affect (e.g. reduce the fringing coupling)of the resulting signals. Alternately, a floating electrode may becoupled to the input and to the transmitter and receiver and the userinput may lower its impedance to system ground and thus reduce theresulting signals. In a further example, a floating electrode may bedisplaced toward the transmitter and receiver which increases theirrelative coupling. The receiver electrodes, or a corresponding sensorelectrode 211, may be operated singly or multiply to acquire resultingsignals created from the transmitter signal. The resulting signals maybe used to determine measurements of the capacitive couplings at thecapacitive pixels, which are used to determine whether an input objectis present and its positional information, as discussed above. A set ofvalues for the capacitive pixels form a “capacitive image” (also“capacitive frame” or “sensing image”) representative of the capacitivecouplings at the pixels. In various embodiments, the sensing image, orcapacitive image, comprises data received during a process of measuringthe resulting signals received with at least a portion of the sensingelements 121 distributed across the sensing region 120. In one example,a capacitive image, or sensing image, comprises data received during aprocess of measuring the resulting signals received across all of thesensing elements 121 during a single scan cycle of the sensing region120. The resulting signals may be received at one instant in time, or byscanning the rows and/or columns of sensing elements distributed acrossthe sensing region 120 in a raster scanning pattern (e.g., seriallypolling each sensing element separately in a desired scanning pattern),row-by-row scanning pattern, column-by-column scanning pattern or otheruseful scanning technique. In many embodiments, the rate that the“sensing image” is acquired by the input device 100, or sensing framerate, is between about 60 and about 180 Hertz (Hz), but can be higher orlower depending on the desired application.

In some touch screen embodiments, the sensing elements 121 are disposedon a substrate of an associated display device. For example, the sensorelectrodes 202 and/or the sensor electrodes 211 may be disposed on apolarizer, a color filter substrate, or a glass sheet of an LCD. As aspecific example, the sensor electrodes 202 and 211 may be disposed on aTFT (Thin Film Transistor) substrate of an LCD type of the displaydevice, a color filter substrate, on a protection material disposed overthe LCD glass sheet, on a lens glass (or window), and the like. Theelectrodes may be separate from and in addition to the displayelectrodes, or shared in functionality with the display electrodes.Similarly, an extra layer may be added to a display substrate or anadditional process such as patterning applied to an existing layer.

In some touchpad embodiments, the sensing elements 121 are disposed on asubstrate of a touchpad. In such an embodiment, the sensor electrodes ineach sensing element 121 and/or the substrate may be substantiallyopaque. In some embodiments, the substrate and/or the sensor electrodesof the sensing elements 121 may comprise a substantially transparentmaterial.

In those embodiments, where sensor electrodes of each of the sensingelements 121 are disposed on a substrate within the display device(e.g., color filter glass, TFT glass, etc.), the sensor electrodes maybe comprised of a substantially transparent material (e.g., ITO, ATO,ClearOhm™) or they may be comprised of an opaque material and alignedwith the pixels of the display device. Electrodes may be consideredsubstantially transparent in a display device if their reflection(and/or absorption) of light impinging on the display is such that humanvisual acuity is not disturbed by their presence. This may be achievedby matching indexes of refraction, making opaque lines narrower,reducing fill percentage or making the percentage of material moreuniform, reducing spatial patterns (e.g. moiré) that are with visible tothe human eye, and the like.

In one configuration, as illustrated in FIG. 2A and further discussedbelow, the processing system 110 of the input device 295 comprises asensor controller 218 that is coupled through connectors 217 to each ofthe transmitter and receiver electrodes, such as sensor electrodes 202and 211, through one or more traces (e.g., traces 212 and 213),respectively. In one embodiment, the sensor controller 218 is generallyconfigured to transmit the transmitter signal and receive the resultingsignals from receiver electrodes. The sensor controller 218 is alsogenerally configured to communicate the positional information receivedby the sensing elements 121 to the electronic system 150 and/or thedisplay controller 233, which is also coupled to the electronic system150. The sensor controller 218 may be coupled to the electronic system150 using one or more traces 221 that may pass through a flexibleelement 251 and be coupled to the display controller 233 using one ormore traces 221A that may pass through the same flexible element 251 ora different connecting element, as shown. While the processing system110 illustrated in FIG. 2A schematically illustrates a single component(e.g., IC device) to form the sensor controller 218, the sensorcontroller 218 may comprise two or more controlling elements (e.g., ICdevices) to control the various components in the processing system 110of the input device 295. The controller devices may be placed ontodisplay substrates such as TFT or Color Filter/Sealing layers (e.g., asa Chip On Glass).

In one configuration, the functions of the sensor controller 218 and thedisplay controller 233 may be implemented in one integrated circuit thatcan control the display module elements and drive and/or sense datadelivered to and/or received from the sensor electrodes. In variousembodiments, calculation and interpretation of the measurement of theresulting signals may take place within the sensor controller 218,display controller 233, a host electronic system 150, or somecombination of the above. In some configurations, the processing system110 may comprise a transmitter circuitry, receiver circuitry, and memorythat is disposed within one or any number of ICs found in the processingsystem 110, depending to the desired system architecture.

FIG. 2B is a schematic view of a portion of the processing system 110 ofthe input device 295 according to one or more of the embodimentsdescribed herein. In one configuration, the sensor controller 218includes a signal generating processor 255 and sensor processor 256 thatwork together to provide touch sensing data to an analysis module 290and the electronic system 150. The analysis module 290 may be part ofthe processing system 110, the sensor processor 256 and/or part of theelectronic system 150. In various embodiments, the analysis module 290will comprises digital signal processing elements and/or other usefuldigital and analog circuit elements that are connected together toprocess the receiver channel output signal(s) received from at least onereceiver channel that is coupled to a receiver electrode, and alsoprovide processed signals to other portions of the electronic system150. The electronic system 150 can then use the processed signals tocontrol some aspect of the input device 295, such as send a message tothe display, perform some calculation or software related task based oninstructions created by one or more software programs that are being runby the electronic system and/or perform some other function.

As illustrated in FIG. 2B, the signal generating processor 255 and thesensor processor 256 work together to provide receiver channel outputsignals to the analysis module 290 and/or the electronic system 150. Asdiscussed above, the positional information of an input object 140(FIG. 1) is derived based on the capacitance C_(s) (e.g., capacitanceC_(S1), C_(S2), . . . C_(SN)) measured between each of the transmitterelectrodes (e.g., sensor electrodes 202 ₁, 202 ₂, . . . 202 _(N)) andthe receiver electrodes (e.g., sensor electrodes 211 ₁, 211 ₂, . . . 211_(N)), wherein N is a positive integer.

Each of the transmitter electrodes (e.g., sensor electrodes 202 ₁, 202₂, . . . 202 _(N) in FIG. 2B) is connected to a trace (e.g., traces 212₁, 212 ₂, . . . 212 _(N) in FIG. 2B). Each trace has a certain amount ofcapacitance (e.g., transcapacitance) that is formed between the traceand the corresponding receiver electrode. As illustrated in FIG. 2B, thecapacitance between a trace and a receiver is given by capacitance C_(T)(e.g., capacitance C_(T1), C_(T2), . . . C_(TN)) and can be measuredbetween each of the trace (e.g., traces 212 ₁, 212 ₂, . . . 212 _(N))and a receiver electrode (e.g., 211 ₁, 211 ₂, . . . 211 _(N)) at variouspoints along the trace (e.g., Y-direction in FIG. 2C), where N is apositive integer. As shown, each trace capacitance C_(T) (e.g.,capacitance C_(T1), C_(T2), . . . C_(TN)) is in parallel with atransmitter capacitance C_(S) (e.g., capacitance C_(S1), C_(S2), . . .C_(SN)). Parasitic capacitance occurs where an input object ispositioned over a trace and the input device detects a change in thecapacitance at an associated pixel (e.g., sensed resulting signalprovided by the associated sensing element 121), due to the change inthe trace capacitance C_(T) (e.g., capacitance C_(T1), C_(T2), . . .C_(TN)).

In one embodiment, as shown in FIG. 2B, the signal generating processor255 comprises a driver 228, which are adapted to deliver capacitivesensing signals (transmitter signals) to the transmitter electrodes. Inone configuration, the driver 228 may comprise a power supply and signalgenerator 220 that is configured to deliver a square, rectangular,trapezoidal, sinusoidal, Gaussian or other shaped waveforms used to formthe transmitter signal(s) to the transmitter electrodes. In oneconfiguration, the signal generator 220 comprises an electrical device,or simple switch, that is able to deliver a transmitter signal thattransitions between the output level of the power supply and a lowdisplay voltage level. In various embodiments, signal generator 220 maycomprise an oscillator. In some configurations, the signal generator 220is integrated into the driver 222, which includes one or more shiftregisters (not shown) and/or switches (not shown) that are adapted tosequentially deliver transmitter signals to one or more of thetransmitter electrodes at a time.

In one embodiment, as shown in FIG. 2B, the sensor processor 256comprises a plurality of receiver channels 275 (e.g., receiver channels275 ₁, 275 ₂, . . . 275 _(N)) that each have a first input port 241(e.g., ports 241 ₁, 241 ₂, . . . 241 _(N)) that is configured to receivethe resulting signal received with at least one receiver electrode(e.g., sensor electrode 211 ₁, 211 ₂, . . . 211 _(N)), a second inputport (e.g., ports 242 ₁, 242 ₂, . . . 242 _(N)) that is configured toreceive a reference signal delivered through the line 225, and an outputport coupled to the analysis module 290 and electronic system 150.Typically, each receiver channel 275 is coupled to a single receiverelectrode. Each of the plurality of receiver channels 275 may include acharge accumulator 276 (e.g., charge accumulators 276 ₁, 276 ₂, . . .276 _(N)), supporting components 271 (e.g., components 271 ₁, 271 ₂, . .. 271 _(N)) such as demodulator circuitry, a low pass filter, sample andhold circuitry, other useful electronic components filters andanalog/digital converters (ADCs) or the like. The analog/digitalconverter (ADC) may comprise, for example, a standard 8, 12 or 16 bitADC that is adapted to receive an analog signal and deliver a digitalsignal (receiver channel output signal) to the analysis module 290 (e.g.a Successive Approximation ADC, a Sigma-Delta ADC, an Algorithmic ADC,etc). In one configuration, the charge accumulator 276 includes anintegrator type operational amplifier (e.g., Op Amps A₁-A_(N)) that hasan integrating capacitance C_(fb) that is coupled between the invertinginput and the output of the device. Due to the type of electronicelements required to detect and process the received resulting signals,the cost required to form the each receiver channel 275 is generallymore expensive than the cost required to form the components in thesignal generating processor 255 that provides the transmitter signal(s)to a transmitter electrode(s). However, in some embodiments of theinvention, it is desirable to reduce the number of transmitterelectrodes to increase the scanning speed of the capacitive sensing typeinput device. In these configurations, it is generally desirable tomaintain the same capacitive pixel density to maintain the input objectposition sensing accuracy. One skilled in the art will appreciate thatdelivering a capacitive sensing signal to a single transmitter electrodeand then measuring the resulting signals on all of the receiverelectrodes in the sensing region would provide a much faster capacitivesensing scanning process than sequentially delivering capacitive sensingsignals in time to two or more transmitters then sensing the receivedresulting signals after each sequential scanning step.

Moreover, there is a benefit to reducing the number of traces used in aninput device, since this will reduce the complexity and cost of theinput device. The sensing region 120 of most typical 3 inch up to 15inch diagonal handheld devices today, such as a tablet, PDA or othersimilar device, require hundreds or even thousands of sensing elements121 to reliably sense the position of one or more input objects. Thereduction in the number of traces that need to be routed to the variousprocessing system 110 components is desirable for a number of reasons,which include a reduction in the overall cost of forming the inputdevice 100, a reduction in the complexity of routing the multitude oftraces within the sensing region 120, a reduced interconnecting tracelength due to reduced routing complexity, a reduction in thecross-coupling of signals between adjacently positioned traces, andallowing for a tighter packing or increased density of sensor electrodeswithin the sensing region 120. The reduction in the number of traceswill also reduce the amount of cross-coupling between the traces due toa reduction in the required trace density and number of traces that willtransmit or receive signals delivered to or from adjacently positionedsensor electrodes or traces. One or more of the embodiments describedherein, includes an electrode array design that is configured to reduceor minimize the number of traces and/or electrodes required to sense theposition of an input object within the sensing region 120 usingcapacitive pixels that contain unique pairs of sensor electrodes toreliably determine the position of an input object. In sometranscapacitive sensing embodiments, transmitter and/or receiver typesensor electrodes are interconnected together to reduce the number oftraces that need to be coupled to the processing system components.Reducing the number of electrode connections, and thus supportingcomponents (e.g., receiver channels), may allow for designs that canreduce the production cost and system complexity, even when a largernumber of electrodes are required.

FIG. 2C is a schematic view of sensing elements 121 disposed in an arrayof sensing elements (not shown) of the input device 100, which is partof the processing system 110 of an input device 295 according to one ormore of the embodiments described herein. As illustrated in FIG. 2C, anddiscussed herein, a sensor electrode found in a sensing elements 121will generally comprise an electrode region and a trace. In one example,a sensor electrode includes an electrode region 203, 204 and a trace212, 213, respectively. For simplicity, only two transmitter electrodes(202 ₁, 202 ₂) are shown, and thus each of the two sensing elements 121illustrated in FIG. 2C comprises a transmitter electrode 202 ₁ or 202 ₂and a portion of a group of the interconnected electrode regions 204that form the receiver electrode 211. As illustrated in FIG. 2C, theelectrode regions 204 of the receiver electrode 211 interact with theelectrode regions 203 of the two transmitter electrodes 202 ₁, 202 ₂ andtwo corresponding traces 212 ₁, 212 ₂ when a sensing signal is providedto the transmitter electrodes in the each sensing element 121. Theprocessing system 110 includes a signal generating processor 255 and asensor processor 256 that work together to provide capacitive sensingreceiver channel output signals to the analysis module 290 andelectronic system 150. As discussed above, the processing system derivesthe positional information of an input object 140 (FIG. 1) based on thecapacitance measured between each of the transmitter electrodes and thereceiver electrodes contained in the sensing region 120. In variousembodiments, the sensor processor 256 comprises digital signalprocessing elements and/or other useful digital and analog circuitelements that are connected together to process the receiver channeloutput signal(s) received from at least one receiver channel that iscoupled to each of the receiver (Rx) electrodes 211. The electronicsystem 150 can then use the processed signals to control some aspect ofthe input device 295, such as send a message to the display, performsome calculation or software related task based on instructions createdby one or more software programs that are being run by the electronicsystem and/or perform some other function.

In one embodiment, as shown in FIG. 2C, the signal generating processor255 comprises a driver 228, which is adapted to sequentially delivercapacitive sensing signals (transmitter signals) to the transmitter (Tx)electrodes 202 ₁, 202 ₂ in the array of sensing elements. In oneconfiguration, the driver 228 may comprise a power supply and signalgenerator that is configured to deliver a square, rectangular,trapezoidal, sinusoidal, Gaussian or other shaped waveforms used to formthe transmitter signal(s) to the transmitter electrodes. In oneconfiguration, the signal generator comprises an electrical device, orsimple switch, that is able to deliver a transmitter signal thattransitions between the output level of the power supply and a lowdisplay voltage level.

In one embodiment, as shown in FIG. 2C, the sensor processor 256comprises a plurality of receiver channel(s) 207 that each have a firstinput port 241 that is configured to receive the resulting signalreceived by at least one receiver electrode 211, and an output portcoupled to the analysis module 290. Typically, each receiver channel207, which can be the same as a receiver channel 275 discussed above,may be coupled to a single receiver electrode 211. In one configuration,the sensor processor 256 further comprises an electromagneticinterference (EMI) filter 299 that is adapted to filter EMI induced byother input device components.

Traces 212 ₁, 212 ₂ connect the driver 222 to the transmitter electrodes202 ₁, 202 ₂, respectively. For example, trace 212 ₁ connects the driver222 to transmitter electrode 202 ₁ and trace 212 ₂ connects the driver222 to transmitter electrode 202 ₂. The capacitance between trace 212 ₁and the receiver electrode 211 is associated with an electric fieldE_(T1). The capacitance between trace 212 ₂ and the receiver electrode211 is associated with an electric field E_(T2). The capacitance betweentransmitter electrode 202 ₁ and the receiver electrode 211 is associatedwith an electric field E_(S1). The capacitance between transmitterelectrode 202 ₂ and the receiver electrode 211 is associated with anelectric field E_(S2).

Where an input object (e.g., finger) is positioned near, such as over aelectrode region 203 of a transmitter electrode 202 ₁, 202 ₂ and anelectrode region 204 of a receiver electrode 211, the associated tracewill also see a change in capacitance (and corresponding electricfield). For example, if an input object (e.g., finger) is overtransmitter electrode 202 ₁, the electric field E_(S1) tends to change,along with the electric field E_(T1) generated between trace 212 ₁ andthe receiver electrode 211. Likewise, if an input object (e.g., finger)is over transmitter electrode Es₂, the electric field E_(S2) tends tochange along with the electric field E_(T2) generated between the trace212 ₂ and the receiver electrode 211.

Likewise, where an input object (e.g., finger) is near a trace 212 ₁,212 ₂, when a sensing signal is provided a change in capacitance (andcorresponding electric field) between the trace and the receiverelectrode 211 will be measured by the sensor processor 256. The positionof the input object near a trace 212 ₁, 212 ₂ will cause a change in theelectric field generated between the trace and the receiver electrodes,and thus affect the measured resulting signal measured by the sensorprocessor 256. For example, if an input object (e.g., finger) is overtrace 212 ₁, the electric field E_(T1) tends to change, which is seen asa change in the resulting signal delivered by the transmitter electrode202 ₁ to the receiver electrode 211. Likewise, if an input object (e.g.,finger) is over trace 212 ₂, the electric field E_(T2) tends to change,which is seen as a change in the resulting signal delivered by thetransmitter electrode 202 ₂ to the receiver electrode 211. Thecapacitance changes at the traces 212 ₁, 212 ₂ also affect thecapacitive coupling of the connected transmitter electrode(s) 202 ₁, 202₂ to the receiver electrode 211, respectively. Such capacitance changesassociated with an input object (e.g., finger) being over a trace may bereferred to as “parasitic capacitance.” As further described below, theinput device is configured to correct parasitic capacitance in order tocarry out object detection algorithms more accurately.

FIG. 3 is an enlarged schematic view of a portion of a sensing region120 formed on a substrate 209 that includes a plurality of sensorelectrodes that are used to sense the position of an input object withinthe sensing region 120 using a transcapacitive sensing method. Asillustrated in FIG. 3, the input device 100 includes two arrays oftransmitter electrodes 316 and two receiver electrodes 311. The firstarray of transmitter electrodes 316 ₁ includes transmitter electrodes302A-302D that are each coupled to a separate trace 301 and the secondarray of transmitter electrodes 316 ₂ include transmitter electroderegions 302E-302H that are each coupled to a separate trace 301. Forease of discussion purposes, FIG. 3 only includes one receiver electrode311 ₁ that is positioned to directly couple with the transmitterelectrodes 302A-302D in the first array of transmitter electrodes 316 ₁and only one receiver electrode 311 ₂ that is positioned to directlycouple with the transmitter electrode regions 302E-302H in the secondarray of transmitter electrodes 316 ₂. The configuration of sensorelectrodes shown in FIG. 3 is not intended to be limiting as to thescope of the invention described herein.

As noted above, to reduce the overall cost of forming the input device100, reduce the system complexity, reduce the cross-coupling of signalsbetween adjacently positioned traces and the costs to detect and processthe resulting signals generated during a capacitive sensing process, thereceiver electrodes 311 ₁ and 311 ₂ are electrically coupled together,such that a single trace 302 is connected to the processing system 110components (not shown), such as the sensor controller 218 (not shown). Areduction in the cost of the overall input system can be realized byreducing the number of electrode traces, especially by reducing thenumber of traces that are coupled to receiver electrodes, due to thecost required to form the components used to receive and process thereceived resulting signals. Therefore, in some embodiments, it isdesirable to interconnect at least two sensor electrodes, or two or moresensor electrodes in two different arrays of sensor electrodes, that arepositioned a distance apart from each other within the sensing region120. By interconnecting the sensor electrodes prior to their connectionto the processing system components the number of traces that arerequired to couple with the processing system 110 components will bereduced. In one example, the traces of multiple receiver electrodes areelectrically coupled together to reduce the number of requiredconnections made to the signal processing components within the sensorprocessor 256 (e.g., receiver channels 275) in the processing system110. Therefore, in this example, the ratio of the number of transmitterto receiver traces is greater than one. In this case, by coupling thereceiver electrodes together the number of required receiver channelswill be reduced, thus reducing the cost and complexity of the processingsystem 110. However, in some configurations, it is also desirable tohave more transmitter electrodes regions than receiver electrodesregions (e.g., ratio of transmitter to receiver electrodes is greaterthen one), since a fully enabled transmitter electrode generally costsless to manufacture than a fully enabled receiver electrode. In anotherexample, the traces of multiple transmitter electrodes are electricallycoupled together to reduce the number of required connections made tothe signal driving components within the generating processor 255 in theprocessing system 110 and/or to improve the scanning speed of the inputdevice. In yet another example, both the number of traces used to couplethe transmitter electrodes and the receiver electrodes to their varioussignal processing components are reduced by interconnecting the tracesof each type of electrode. However, in cases where both types oftranscapacitive sensing electrodes are each coupled to electrodes of thesame type (e.g., transmitter electrodes to transmitter electrodes andreceiver electrodes to receiver electrodes) this can lead to capacitivesensing issues associated with correctly determining the position of aninput object. Therefore, as will be discussed further below, someembodiments of the invention include interconnected electrodes that onlyform unique pairs of transmitter and receiver electrodes.

In some sensor electrode configurations, as illustrated in FIG. 3, theinterconnection between some types of sensor electrodes, such asreceiver electrodes 311 ₁ and 311 ₂ can lead to misleading or falseinput object position determination(s) by the processing system. Themisleading or false determination of the input objects position can bedue to the cross-coupling between transmitter electrodes and/ortransmitter electrode traces and the two or more receiving electrodesthat are interconnected together within the sensing region 120. In oneexample, due to the interconnection of the two receiver electrodes 311 ₁and 311 ₂, as shown in FIG. 3, the processing system will not be able todetermine whether an input object 140 is in the first input objectposition 140 ₁ or in the second input object position 140 ₂. Thisproblem may arise from the cross-coupling of the trace 301H and thefirst receiver electrode 311 ₁ and the intended direct coupling of theelectrode region 302H and the second receiver electrode 311 ₂, since theconnection formed between the receiver electrodes 311 ₁ and 311 ₂ willnot allow the processing system 110 to determine if the input object isover the first receiver electrode 311 ₁ or the second receiver electrode311 ₂. One skilled in the art will appreciate that when the sensorelectrode region 302H is driven for capacitive sensing, the trace 301Hwill capacitively couple to the first sensor electrode 311 (e.g., withinregion P₁) and the electrode region 302H will directly couple to thesecond sensor electrode 311 ₂. Since the input object could be in morethan one position within the sensing region 120 (e.g., input objectposition 140 ₁ or 140 ₂), and still provide the same or a similarresulting signal to the sensor processor portion of the processingsystem, it is not possible to determine the actual position of the inputobject.

Therefore, in an effort to resolve some of the capacitive sensinglimitations with configurations similar to the example shown in FIG. 3,a revised sensor electrode layout that is able to accurately sense theposition of an input object 140, while also having a reduced number ofinterconnecting traces is needed. FIGS. 4-8 illustrate a few examples ofvarious configurations that can be used to meet these goals. Theseexamples are provided herein to help explain various aspects of theinvention and are not intended to limit the scope of the inventiondescribed herein. While FIGS. 4-8 illustrate a sensor electrodeconfiguration that includes one or more arrays of receiver electrodes,such as arrays of sensor electrodes 416 containing sensor electroderegions 411A and 411B, that are interconnected to form two groups ofsensor electrodes, this configuration is not intended to be limiting asto the scope of the invention described herein. One skilled in the artwill appreciate that one or more of the arrays of sensor electrodescould be formed so that it contains more or less groups of receiverelectrodes that contain one or more sensor electrodes without deviatingfrom the scope of the invention described herein. Also, while FIGS. 4-8illustrate a sensor electrode configuration that includes one or morearrays of transmitter electrodes, such as arrays of sensor electrodes415, which contain a plurality of sensor electrodes 402, for example mayinclude sensor electrode regions 402A-402H (FIG. 4), that are eachseparately connected to the processing system 110 through a trace 412,this configuration is not intended to be limiting as to the scope of theinvention described herein. One skilled in the art will appreciate thatone or more of the separately connected traces 412 can be interconnectedinside or outside of the sensing region 120 before they are coupled withthe processing system 110 components without deviating from the scope ofthe invention described herein.

FIG. 4 is an enlarged schematic view of a portion of a sensing region120 formed on a substrate 209 that includes a plurality of sensorelectrodes that are used to accurately sense the position of an inputobject within the sensing region 120 using a transcapacitive sensingmethod. The input device 100 in this example includes two sets of sensorelectrode arrays 420 ₁, 420 ₂ that each include an array of transmitterelectrodes 415 ₁ or 415 ₂ and an array of receiver electrodes 416 ₁ or416 ₂. In some of the transcapacitive sensing embodiments describedherein, a set of sensor electrode arrays generally includes at least onearray of transmitter electrodes and at least one array of receiverelectrodes that are used together to form an array of sensing elements121. The first array of transmitter electrodes 415 ₁ includestransmitter electrode regions 402A-402D that are each coupled to aseparate trace 412 and the second array of transmitter electrodes 415 ₂includes transmitter electrode regions 402E-402H that are each coupledto a separate trace 412. The first array of receiver electrodes 416 ₁and second array of receiver electrodes 416 ₂ each include a pluralityof sensor electrodes that include receiver electrode regions 411A, 411Band traces 413A, 413B. The receiver electrode regions 411A and 411B inthe first and second electrode arrays 416 ₁, 416 ₂ are each separatelycoupled together using a trace 413A or 413B, respectively. By couplingthe sensor electrodes in the first and second arrays of receiverelectrodes 416 ₁, 416 ₂ together, the number of required connections tothe processing system 110 is reduced. A conventional sensing electrodedesign that requires one trace per receiver electrode would require 10separate traces and connections (e.g., 10 electrode regions 411A and411B) to the processing system 110 components (FIG. 2A), such as thesensor controller 218 (FIG. 2A). By connecting the sensor electrodes inthe first and second arrays of receiver electrodes into one or moregroups of sensor electrodes the number of separate traces andconnections can be reduced. In this example, two groups ofinterconnected sensor electrodes are formed by interconnecting theelectrode regions 411A and 411B using the traces 413A and 413B,respectively, in each array of sensor electrodes. Therefore, each of thetwo groups of electrode in the arrays of sensor electrodes 416 ₁, 416 ₂are interconnected via the interconnection traces 413AA, 413BB,respectively, so that only two separate traces 423A and 423B arerequired to separately connect the two groups of sensor electrodes withthe processing system 110 components.

Due to the separate interconnection of transmitter electrodeconfiguration, which is illustrated in FIG. 4, each of the formedsensing elements contain unique pairs of transmitter and receiverelectrodes that have a reduced total interconnection trace count frommost conventional electrode configurations. As noted above, embodimentsof the invention may provide an electrode configuration that comprisesmultiple arrays of capacitive pixels that each includes unique pairs ofsensor electrodes to reliably determine the position of an input object.Unique pairs to sensor electrodes generally include configurations wherea first pair of sensor electrodes in a first capacitive pixel are bothnot interconnected with another pair of sensor electrodes in any of theother capacitive pixels in the sensing region. For example, a pixel thatincludes a portion of the sensor electrode region 402D and a portion ofsensor electrode region 411B in the array of sensor electrodes 415 ₁would not be unique from a pixel that includes a portion of the sensorelectrode region 402G and a portion of sensor electrode region 411B inthe array of sensor electrodes 415 ₂ if the traces 412D and 412G wereconnected together so that these sensor electrodes send or receivecapacitive sensing signals at the same time, since both of theelectrodes of the same type are connected together and are used in thesame two pixels (e.g., electrode regions 402D and 402G are connectedtogether and electrode regions 411B in the array of sensor electrodes415 ₁ and electrode regions 411B in the array of sensor electrodes 415 ₂are connected together via the interconnection trace 413BB). Thepresence of non-unique directly coupled pairs of sensing electrodes willtypically lead to false and misleading input object positiondeterminations as discussed above.

In an effort to further reduce the problems associated with theconfigurations similar to the one illustrated in FIG. 3, in someembodiments, the arrays of transmitter electrodes 415, and theirassociated traces 412, are positioned next to each other with nointervening array(s) of receiver electrodes 416 between them. Bypositioning the arrays of transmitter electrodes 415 and associatedtraces 412 next to each other the cross-coupling of the traces 412 andeither of the arrays of receiver electrodes 416 ₁, 416 ₂ is minimized,and the cross-coupling of transmitter electrodes in an array oftransmitter electrodes that are not positioned to directly couple withthe arrays of receiver electrodes 416 ₁, 416 ₂ is avoided. In thisconfiguration, the arrays of transmitter electrodes 415 and associatedtraces 412 are positioned next to each other and are disposed betweentwo or more arrays of receiver electrodes 416. In one example, when thesensor electrode region 402H is driven for capacitive sensing, the trace412H is not positioned so that it will capacitively couple to the firstsensor electrode region 411A or the second sensor electrode region 411Bin the first or second arrays of sensor electrodes 415 ₁ or 415 ₂.

In one embodiment, two or more arrays of transmitter electrodes (e.g.,arrays 415 ₁ and 415 ₂) are positioned adjacent to each other so thatthe gaps between the electrode regions 402A-402D and electrode regions402E-402H is minimized by reducing the gaps formed between the tracesand transmitter electrodes, while still being ohmically isolated fromeach other. The reduction in the gaps formed between the traces andtransmitter electrodes will also improve the density of sensing elements121 formed within the sensing region 120. In this example, one sensingelement 121 is formed between electrode region 402D and the uppermostelectrode region 411A in the first array of receiver electrodes 416 ₁and another sensing element 121 is adjacently formed between electroderegion 402H and the uppermost electrode region 411A in the second arrayof receiver electrodes 416 ₂.

In some sensor electrode configurations discussed herein, the arrays ofsensor electrodes (e.g., transmitter and/or receiver electrodes) includea plurality of sensor electrode regions (e.g., electrode regions402A-402D or 411A-411B) that are aligned along a first direction, suchas the Y-direction shown in FIG. 4. In one example, the centroid of thearea of the electrode regions in an array of sensor electrodes (e.g.,electrode regions 402A-402D) are aligned along a first direction. Inanother example, an edge of the electrode regions in an array of sensorelectrodes are aligned along a first direction. In yet another example,where the edge(s) of the electrode regions are non-linear, the alignmentof the electrode regions may be found by comparing the orientation andalignment of the major axis of symmetry of the electrode regions.

In one embodiment, two or more arrays of sensing electrodes (e.g.,arrays of sensor electrodes 415 ₁ and 415 ₂) are positioned adjacent toeach other and are symmetric about a linear (e.g., axis) and/ornon-linear symmetry line, so that a regular pattern of sensing elements121 are formed across the sensing region 120. In one example, as shownin FIG. 4, the first array of transmitter electrodes 415 ₁ and secondarray of transmitter electrodes 415 ₂ are symmetric about a symmetryline 401, which in this example happens to be linear. As illustrated inFIG. 4, the electrode regions 402A-402D, and their associated traces412, and electrode regions 402E-402H, and their associated traces 412,are also mirror images of each other. Also, in some configurations, asillustrated in FIG. 4 the sets of sensor electrode arrays 420 ₁, 420 ₂may be positioned a distance apart in a second direction (e.g.,X-direction) that is orthogonal to or at an angle with a first directionthat is parallel to the symmetry line and/or parallel to an alignmentdirection of an array of sensor electrodes (e.g., Y-direction for theelectrode regions 402A-402D).

Due to the layout of the sensing electrodes disclosed herein, duringoperation an input object 140 that is positioned over or near theelectrode region 402E and traces 412 will primarily couple to thereceiving electrodes in the second array of receiver electrodes 416 ₂.Thus, by orienting the electrodes in this way the cross-coupling of theinput object and the other connected receiver electrodes in the firstarray of receiver electrodes 416 ₁ is reduced or completely removed.

In another configuration, as illustrated in FIG. 5, the arrays ofreceiver electrodes 416, and their associated traces 413A-413B, arepositioned next to each other with no intervening array(s) oftransmitter electrodes 415 positioned between them. The input device 100illustrated in FIG. 5 generally includes four sets of sensor electrodearrays 520 ₁-520 ₄ that each contain two or more arrays of sensorelectrodes, such as a first array of transmitter electrodes 415A and afirst array of receiver electrodes 416A. By positioning the arrays ofreceiver electrodes and their associated traces next to each other, thecross-coupling of the arrays of receiver electrodes and non-directlycoupled electrode regions is minimized, and the problem of false ormisleading input object position determination can be eliminated.

In some embodiments, one or more groups of sensor electrodes in an arrayof sensor electrodes that are positioned within a first set of sensorelectrode arrays are coupled with one or more groups of sensorelectrodes in an array of sensor electrodes that are positioned within asecond set of sensor electrode arrays to help reduce the number oftraces that are required to sense the position of an input object withinthe sensing region 120. In one example, as illustrated in FIG. 5, afirst group of receiver electrodes 414A, which include electrode regions411A, in the first array of receiver electrodes 416A in the first set ofsensor electrode arrays 520 ₁ are coupled to the first group of receiverelectrodes 414C, which include electrode regions 411A, in the thirdarray of receiver electrodes 416C in the third set of sensor electrodearrays 520 ₃ using the trace 413AA. In general, the one or more groupsof sensor electrodes in different sets of sensor electrode arrays can beconnected together to reduce the number of traces and complexity of theprocessing system 110 components. In some embodiments, at least oneelectrode region in a first array of receiver electrodes isinterconnected with at least one electrode region in a second array ofreceiver electrodes, which are disposed in the sensing region 120.

Referring to FIG. 5, the arrays of receiver electrodes 416A and 416B andarrays of receiver electrodes 416C and 416D, and their associated traces413A-413B, are each positioned near to each other (e.g., adjacent toeach other). In this configuration, the arrays of receiver electrodes416 and associated traces are positioned next to each other and aredisposed between two or more arrays of transmitter electrodes 415. Thus,when the sensor electrode region 402H is driven for capacitive sensing,the trace 412H is positioned so that it will essentially notcapacitively couple to the first sensor electrode region 411A or thesecond sensor electrode region 411B in the second array of receiverelectrodes 416 ₂ or the first sensor electrode region 411A or the secondsensor electrode region 411B in the first or third array of receiverelectrodes 416 ₁ or 416 ₃.

In another configuration, as illustrated in FIG. 6A, each of the sets ofsensor electrode arrays 620 ₁-620 ₄ include an array of receiverelectrodes 416, and their associated traces 413A-413B or 413C-413D, thatare positioned between array(s) of transmitter electrodes 415. In oneexample, a first set of sensor electrode arrays 620 ₁ includes threearrays of sensor electrodes, such as a first array of transmitterelectrodes 415A, a first array of opposing transmitter electrodes 417Aand a first array of receiver electrodes 416A. It is believed thatpositioning an array of one type of sensing electrode between at leasttwo arrays of another type of sensing electrodes that form uniquepixels, such as an array of receiving electrodes between two arrays oftransmitter electrodes or vice versa, the physical orientation of thedifferent types of sensor electrodes can help shield or minimize thecross-coupling of electrodes that are positioned a distance away fromthe set of electrode arrays, and thus prevent the mischaracterization ofan input objects position when electrodes in two or more different setsof sensor electrode arrays are connected together. Also, in one example,as illustrated in FIG. 6B, by positioning an array of one type ofsensing electrode between at least two arrays of another type of sensingelectrodes will create a symmetric electric field between the electrodeswhen the center electrode is driven relative to the two outer electrodesor the two outer electrodes are driven relative to the inner electrode,which will improve the quality of the capacitive sensing signal andprocess.

FIG. 6B illustrates an example of an electrode connection configurationthat is formed in each of the sets of sensor electrode arrays 620 ₁-620₄ to create a symmetric electric field between pairs of opposingelectrodes during operation of the input device. In this example, theelectrodes 402 in the same row, such as electrodes 402D and 402H,electrodes 402L and 402P, electrodes 402C and 402G, etc. are eachcoupled together to form a symmetric electrode configuration relative toan opposing electrode 411. One will note that the number of traces 412that need to be connected to the processing system components 110, inthis example, are cut in half, due to the interconnection the electrodes402 positioned in each row. In this configuration, only traces 412A-Dneed to be routed and connected to the processing system components,which is a smaller subset of the number of traces 412 shown in FIG. 6A.Also, if the electrodes 402 (e.g., electrodes 402D and 402H) are drivenrelative to the electrodes 411 (e.g., electrodes 411A and/or 411B), orvice versa, the electric fields created between each of the electrodes402 and the centrally positioned electrode 411 will be symmetric. Thus,as noted above, the quality of the capacitive sensing signal can beimproved and the cost and complexity of the input device can be reduceddue to the reduction in the number of required traces and capacitivesensing channels.

As illustrated in FIGS. 6A and 6B, at least one electrode region in afirst array of receiver electrodes in a first set of sensor electrodearrays is interconnected with at least one electrode region in a secondarray of receiver electrodes in a second set of sensor electrode arrays,which are all disposed in the sensing region 120. By positioning thearrays of receiver electrodes and their associated traces between twoarrays of transmitter electrodes that are positioned to directly coupleto the receiver electrodes in the array of receiving electrodes, thecross-coupling of the arrays of receiver electrodes and othernon-directly coupled transmitter electrode regions is minimized. In oneexample, when the sensor electrode region 402L is driven for capacitivesensing, the trace 412L is positioned so that it will not capacitivelycouple to the first sensor electrode region 411A or the second sensorelectrode region 411B in the first array of receiver electrodes 416A orthe first sensor electrode region 411A or the second sensor electroderegion 411B in the third array of receiver electrodes 416C.

In some embodiments of the invention, two or more traces are coupledtogether within the sensing region 120 to further reduce the number ofconnections that are required to make to the processing system 110components. In one example, as illustrated in FIG. 6A, the traces 402Hand 402L, 402P and 402T, and 402X and 402BB are each connected togetherto reduce the number of traces 412 that are required to connect theelectrode regions to the processing system components. In this example,the total number of required traces 412 that are coupled to theprocessing components can be reduced by four traces.

FIGS. 7 and 8 illustrate a sensing region 120 of an input device 100that is divided up into sectors 721 or 821 that are each configured tocontain at least one set of sensor electrode arrays. For clarity ofdiscussion, only three of the sectors 721 in FIG. 7 and three of thesectors 821 in FIG. 8 have a set of sensor electrode arrays showntherein. However, one skilled in the art will appreciate that each ofthe sectors 721 shown in FIGS. 7 and 8 could have at least one set ofsensor electrode arrays disposed therein. Moreover, at least oneelectrode in each of these sets of sensor electrode arrays could becoupled with one or more electrodes in another set of sensor electrodearrays disposed in the same sector or other sectors within the sensingregion 120. These electrode configurations will also generally includemultiple arrays of capacitive pixels that each includes unique pairs ofsensor electrodes.

As illustrated in FIG. 7, three sets of sensor electrode arrays 720₁-720 ₃, which are positioned three sectors 721 away from each other,are coupled together to reduce the total number of traces (e.g., traces412 and 413) that need to be connected to the processing systemcomponents (not shown). In this example, at least one electrode in eachof the horizontally oriented three sets of sensor electrode arrays arecoupled together using an interconnect 714 that is coupled to the traces413 (e.g, trace 413A in FIG. 6A) in each set of sensor electrode arraysto reduce the number of traces (e.g., traces 412 and/or 423) that arerequired to connect each of the sensor electrode regions to theprocessing system components.

As illustrated in FIG. 8, three sets of sensor electrode arrays 820₁-820 ₃, which are positioned three sectors 821 away from each other,are coupled together to reduce the total number of traces that need tobe connected to the processing system components (not shown). In thisexample, at least one electrode in each of the three vertically orientedsets of sensor electrode arrays are coupled together using aninterconnect 814 that is coupled to the traces 413 (e.g., trace 413A inFIG. 6A) in each set of sensor electrode arrays to reduce the number oftraces (e.g., traces 412 and/or 423) that are required to connect eachof the sensor electrode regions to the processing system components.

In one embodiment, one or more novel sensor electrode arrayconfigurations are used to reduce or minimize the number of tracesand/or sensor electrodes required to sense the positional information ofan input object within the sensing region of the input device.

The embodiments and examples set forth herein were presented in order tobest explain the present technology and its particular application andto thereby enable those skilled in the art to make and use the presenttechnology. Those skilled in the art will recognize that the foregoingdescription and examples have been presented for the purposes ofillustration and example only. The description as set forth is notintended to be exhaustive or to limit the present technology to theprecise form disclosed. While the foregoing is directed to embodimentsof the present invention, other and further embodiments of the inventionmay be devised without departing from the basic scope thereof, and thescope thereof is determined by the claims that follow.

The invention claimed is:
 1. A capacitive image sensor, comprising: afirst array of sensor electrodes including electrodes of a first andsecond type, the first array of sensor electrodes disposed on a surfaceof a substrate, the first type of sensor electrodes in the first arrayaligned in substantially a first direction on the surface and the secondtype of sensor electrodes in the first array aligned in substantiallythe first direction, wherein each electrode of the first type in thefirst array is positioned to capacitively couple to one of the sensorelectrodes of the second type in the first array; a second array ofsensor electrodes including electrodes of the first and second type, thesecond array of sensor electrodes disposed on the surface of thesubstrate, the first type of sensor electrodes in the second arrayaligned in substantially the first direction and the second type ofsensor electrodes in the second array aligned in substantially the firstdirection, wherein each of the electrodes of the first type in thesecond array is positioned to capacitively couple to one or more of thesensor electrodes of the second type in the second array; and whereinthe second array of sensor electrodes is positioned a distance in asecond direction from the first array of first sensor electrodes, andthe second direction is not parallel to the first direction, and whereinat least one of the sensor electrodes of the second type in the firstarray is electrically coupled to at least one of the sensor electrodesof the second type in the second array.
 2. The capacitive imaging sensorof claim 1, wherein the first type of sensor electrodes in the secondarray is a mirror image of the first type of sensor electrodes in thefirst array about a first axis of symmetry that is parallel to the firstdirection.
 3. The capacitive imaging sensor of claim 1, furthercomprising: a third array of sensor electrodes including electrodes ofthe first type disposed on the surface of the substrate, wherein thefirst type of sensor electrodes in the third array are aligned insubstantially the first direction, and each of the electrodes of thefirst type in the third array are positioned to capacitively couple toat least a portion of a sensor electrode of the second type in the firstarray of sensor electrodes; and a fourth array of sensor electrodesincluding electrodes of the first type disposed on the surface of thesubstrate, wherein each of the electrodes of the first type in thefourth array are aligned in substantially the first direction, and eachof the electrodes of the first type in the fourth array is positioned tocapacitively couple to at least a portion of an electrode of the secondtype in the second array of sensor electrodes.
 4. The capacitive imagingsensor of claim 1, wherein the second type of sensor electrodes areconfigured as receiver electrodes and the first type of sensorelectrodes are configured as transmitter electrodes, and none of thefirst type of sensor electrodes in the first array are ohmically coupledto an electrode of the first type in the second array of electrodes. 5.The capacitive imaging sensor of claim 1, wherein the sensor electrodesof the first type of the first and second arrays are disposed on thesurface of the substrate between the sensor electrodes of the secondtype of the first array and the sensor electrodes of the second type ofthe second array.
 6. The capacitive imaging sensor of claim 1, whereinthe first array of the second type of sensor electrodes furthercomprises: a first group of second electrode regions comprising two ormore second electrode regions; and a second group of second electroderegions comprising two or more second electrode regions, wherein each ofthe two or more second electrode regions in the first group are inelectrical communication with each other and each of the two or moresecond electrode regions in the second group are in electricalcommunication with each other.
 7. The capacitive imaging sensor of claim1, wherein the first type of sensor electrodes and the second type ofsensor electrodes are either transmitter electrodes or receiverelectrodes, and the ratio of transmitter electrodes to receiverelectrodes is greater than
 1. 8. The capacitive imaging sensor of claim1, wherein each of the first type of sensor electrodes further comprisea trace and each of the second type of sensor electrodes furthercomprise a trace, and wherein the traces are coupled to a sensorprocessor.
 9. The capacitive imaging sensor of claim 1, wherein thefirst type of sensor electrodes and the second type of sensor electrodesare substantially transparent.
 10. The capacitive imaging sensor ofclaim 1, wherein the substrate comprises part of a display.